String hql= "Select C from Col C, userrole role where C.id=role.columnid and c.id=? and role.userid=?" this . Gethibernatetemplate (). Find (Hql,new Object[]{colid,userid}). Get (0); The Above returns an object entity that is of type Col String hql= "from Col C, userrole role where C.id=role.columnid and c.id=? and role.userid=?" this . Gethibernatetemp
1.HQL differs from Sql,from must be the name of the class that corresponds to the table reversal in the project.2. How to generate HQL statements using parameters:"= session.createquery (HQL); Query.setparameter (0, userId); // instead of the No. 0 question mark3.HQL can not write limit, but he has the method can be s
HQL basic Query simple Query result for output and Iterator output, hqliterator
The first HQL course:
Hibernate Query Language: hibernate Query Language
Syntax:
Query:
String hql = "from dept ";
Query query = session. createQuery (hql); // returns the list set.
Query is an object with many methods. The. list () meth
SQL ( Structured Query Language ) is the relational database query language. the from is followed by the "table name", where the condition is followed by "field in table"HQL ( Hibernate Query Language ) is an object-oriented query , The from is followed by the table name, where the condition is followed by the field in the table. When you use queries in Hibernate,Generally use HQL query statements. Becau
At the beginning, the HQL statement in the project was relatively casual, and later I checked the Query and
Use the name parameter; colon + field name (or alias); equals to the original "? "Name;String hql = "from User as user where user. name =: name ";//....Query. setString ("name", name); // The first parameter must be named the same as that in hql;
= "u
of the query parameter changes, the name of the state parameter is not necessary to adjust the program code. C, setparameter () method: InHibernateof theHQLthe query can beSetparameter ()method states any type of parameter, as follows: String hql="From user user where user. name=:customername "; Query query=session.createquery (HQL); query.setparameter ("customername", name,hibernate.string);
inner join(内连接) left outer join(左外连接)right outer join(右外连接)full join(全连接,并不常用)SQL中的条件用on即:left join... on...HQL中的条件用with即:left join... with...
语句inner join, left outer join以及 right outer join可以简写。 fromCat as cat joincat.mate asmate left joincat.kittens askitten 通过HQL的with关键字,你可以提供额外的join条件。 fromCat as cat left joincat.kittens askitten with kitten.bodyWeight > 10.0还有,一个"fetch"连接允许仅仅使用一个选择语句就将相关联
1.java.sql.date and Java.util.DateJava.sql.Date is inherited from Java.util.Date and assumes that dates1 (java.sql.Date) is assigned to Dates2 (java.util.Date)Dates2=new java.sql.Date (Dates1.gettime ()) can be performed by the following conversions;2. The difference between the methods in Preparestament Settimestamp () and setdate () and getdate (), Gettimestamp () in resultset:Gettimestamp (), Settimestamp () will get/set "date + Time" in the database, or it can be said to be a timestampGetDat
,: start_date,: x1
SQL direct constant 'foo', 69, '2017-01-01 10:00:01. 0'
Java public static final type constant eg. color. Tabby
You can use the keyword in and between as follows:
Code contentFrom domesticcat cat where Cat. Name between 'a 'and' B'From domesticcat cat where Cat. Name in ('foo', 'bar', 'baz ')
The negative format can also be written as follows:
Code contentFrom domesticcat cat where Cat. Name Not between 'a 'and' B'From domesticcat cat where Cat. Name not
Powerful ORM tool: nhibloud (iii) Five cores + simple object CRUD + HQL, ormcrud
In the previous two articles, we have a rough understanding of nhib.pdf.
Introduction to ORM: nhib.pdf (1) the role of nhib.pdf solves the conversion problem between objects and databases.
ORM tool: nhib.pdf (2) use CodeSmith to quickly generate ing files and ing classes. Use CodeSmith to export ing classes from tables (usually called Entity) and ing files (tell you how
@Entity (name= "icertinfo") HQL query when you need to write entry name value, otherwise it will be error icertinfoPackagestoscan, configuration errors HQL will also errorPackagecom.itrus.business.properties;importjava.util.hashmap;importjava.util.map;import java.util.Properties;importorg.springframework.beans.BeansException;import org.springframework.beans.factory.config.configurablelistablebeanfactory;imp
Prior to Hibernate2.0 version list.get (0) returned an integer type.However, after Hibernate3.0, version list.get (0) returns a long type.Public Integer Getuserscount () {String hql = ' SELECT count (*) from Users ';List List = Super.pagequery (HQL);Number num = (number) list.get (0);return Num.intvalue (); }This article is from the "Oriental Pavilion" blog, please be sure to keep this source http://lailai.
HQL query methods commonly used in spring (Gethibernatetemplate ())
---------------------------------
One, find (String queryString);
Example: This.gethibernatetemplate (). Find ("From Bean". User ");
Returns all user objects
Two, find (String queryString, Object value);
Example: This.gethibernatetemplate (). Find ("From Bean". User u where u.name=? "," Test ");
or fuzzy query: This.gethibernatetemplate (). Find ("From Bean". User u where u.name lik
,user_id from T_user JPQL: Object-oriented JPQL statements
Analysis:The first statement is used to execute a query against the T_user table tables, querying the name, age, and user_id three data columns;The second statement is used to execute a query against the user entity, querying the name, age, and UserId properties of the user entity.Third, HQLHQL (Hibernate query Language) is an object-oriented query, followed by a "table name", where the condition is followed by "fields in the table." Wh
Problem Description:Today, when using HQL to query database information according to the name of the parameter, the error is as follows:Org.hibernate.QueryException:Space is isn't allowed after parameter prefix ': ' [from Users user where user.address=: UserAddress] at Org.hibernate.engine.query.spi.ParameterParser.parse (Parameterparser.java:95) at Org.hibernate.engine.query.spi.ParamLocationRecognizer.parseLocations (Paramlocationrecognizer.java: 75
source code and reports, or as an integration component of other systems. Velocity can also provide template services for the turbine Web development architecture. Three The sql-query dynamic SQL 1 is implemented through velocity. First introduce the structure of the project, so that the idea will be more clear 2. Implement the Hbm.xml configuration Velocity is identified by "#", such as #set, #if, #else, #end, #foreach, #end, #iinclude, #parse, #macro等; For example: #if ($XM) and T.XM=:XM #
Session session = This.getsession ();
String hql = "from Tblfwxx FW where fw.title like?";
Query query = session.createquery (HQL);
Query.setstring (0, "% Yan er%");
Used above. " As a placeholder, and then set the value of the parameter one by one, using the SetString method of query. But this reduces the readability of the code.
So try to use "named parameter query" to solve these problems later
Repl
(); StudentDTO dto = (StudentDTO)resultWithAliasedBean.get(0);
This is how resulttransformer have been available since we introduced projectionTo the criteria API in hibernate 3.
It is just one example of the built in transformers and users can provideTheir own transformers if they so please.Jealous Programming
Since I am more a hql/SQL guy I have been jealous on criteria for having thisFeature and I have seen limit requests for adding it to all ou
Hql can also be used on the selected attributes.Aggregate functions. Hql supports the same clustering function as SQL:
Hql Aggregate functions
AVG
Calculate the average Attribute Value
Count
Count the number of selected objects
Max
Maximum Value of statistical attribute values
Min
Measure
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.